This will be a multicenter open-label Phase II trial in AIDS paitents with diarrhea not controlled by conventional antidiarrheal drugs (e.g., Imodium, Lomotil, Paregoric, or Sandostatin). Approximately 15 evalable patients are expected to complete the study. An evaluable patient will be one who has either completed the entire course of therapy or one who has discontinued therapy due to adverse events. All patients receiving one dose of study drug will be evaluable for safety. Pharmacokinetic studies will be conducted in a minimum of two patients at each dose level.